Rena is the mother of a boy named Tsubasa. One day, Tsubasa brought a girl from school to their home to study together.
However, after the girl teased him for a while, Tsubasa became aggressive and... forcefully jumped on her.
Rena witnessed the incident and intervened just in time to stop it. However, the girl reported the incident to her parents, causing some trouble for Rena and her family.
Since Tsubasa’s father is away, Rena decides to take matters into her own hands and teach her son about proper sexual education using her own body…